Shaking a methane fizz: Seismicity from the Araguainha impact event and the Permian–Triassic global carbon isotope record

Tohver, Eric; Cawood, Peter A.; Riccomini, Cláudio; Lana, Cristiano; Trindade, R. I.

doi:10.1016/j.palaeo.2013.07.010

Cited by 33 publications

(20 citation statements)

References 80 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Tohver et al, 2013;Jiang et al, 2014), as also done in this special issue. This is important, since research of seismites is carried out ever more frequently, and ever more details become available -even though several problems still remain unsolved.…”

Section: Stage Of Adolescencementioning

confidence: 71%

The life cycle of seismite research

Loon

2014

Geologos

View full text Add to dashboard Cite

Section: Stage Of Adolescencementioning

confidence: 71%

The life cycle of seismite research

Loon

2014

Geologos

View full text Add to dashboard Cite

“…The age of the Araguainha impact has been estimated by several studies that concur that the impact event occurred around the time of the Permian–Triassic boundary (e.g., Tohver et al. [, ] or Erickson et al. []).…”

Section: Introductionmentioning

confidence: 99%

Linking shock textures revealed by BSE, CL, and EBSD with U‐Pb data (LA‐ICP‐MS and SIMS) from zircon from the Araguainha impact structure, Brazil

Hauser

Reimold

Cavosie

et al. 2019

Meteorit & Planetary Scien

View full text Add to dashboard Cite

A silicious impact melt rock from polymict impact breccia of the northern part of the alkali granite core of the Araguainha impact structure, central Brazil, has been investigated. The melt rock is thought to represent a large mass of impact‐generated melt in suevite. In particular, a diverse population of zircon grains, with different impact‐induced microstructures, has been analyzed for U‐Pb isotopic systematics. Backscattered electron and cathodoluminescence images reveal heterogeneous intragrain domains with vesicular, granular, vesicular plus granular, and vesicular plus (presumably) baddeleyite textures, among others. The small likely baddeleyite inclusions are not only preferentially located along grain margins but also occur locally within grain interiors. LA‐ICP‐MS U‐Pb data from different domains yield lower intercept ages of 220, 240, and 260 Ma, a result difficult to reconcile with the previous “best age” estimate for the impact event at 254.7 ± 2.7 Ma. SIMS U‐Pb data, too, show a relatively large range of ages from 245 to 262 Ma. A subset of granular grains that yielded concordant SIMS ages were analyzed for crystallographic orientation by EBSD. Orientation mapping shows that this population consists of approximately micrometer‐sized neoblasts that preserve systematic orientation evidence for the former presence of the high‐pressure polymorph reidite. In one partially granular grain (#36), the neoblasts occur in linear arrays that likely represent former reidite lamellae. Such grains are referred to as FRIGN zircon. The best estimate for the age of the Araguainha impact event from our data set from a previously not analyzed type of impact melt rock is based on concordant SIMS data from FRIGN zircon grains. This age is 251.5 ± 2.9 Ma (2σ, MSWD = 0.45, p = 0.50, n = 4 analyses on three grains), indistinguishable from previous estimates based on zircon and monazite from other impact melt lithologies at Araguainha. Our work provides a new example of how FRIGN zircon can be combined with in situ U‐Pb geochronology to extract an accurate age for an impact event.

show abstract

“…The nature of this process is unknown to any tectonic environment operative on Earth and, consequently, the mechanism that best explains the sudden reduction in rock strength remains obscure. One explanation is that and the Araguainha structure in central Brazil (Lana et al, 2003a(Lana et al, , 2004(Lana et al, , 2006(Lana et al, , 2008Abels, 2005;Wieland et al, 2005;Salisbury et al, 2008;Tohver et al, 2013). These folds are the best expression of extreme compressional strain recorded in central uplifts of a number of complex craters in sedimentary and mixed (sedimentary+crystalline) target rocks (e.g., Lana et al, 2003aLana et al, , 2006Wieland et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

“…The central uplift is divided into a 2 km-thick collar of Devonian to Carboniferous clastic sedimentary rocks of the Paraná Basin (Furnas and Ponta Grossa Formations) and a 4 km-wide core of late Cambrian granitic basement (Figs. 1A-D) (Engelhardt et al, 1992;Tohver et al, 2012Tohver et al, , 2013. The annular trough exposes Devonian pelites/sandstones of the Ponta Grossa Formation and Carboniferous red sandstones/conglomerates of the Aquidauana Formation.…”

Section: Introductionmentioning

confidence: 99%